Question

Give 2-2 examples of positive ,negative and zero work .

Answer 1

positive work
acceleration of body in direction of force applied

1. A rope pulls a toy car attached to it in the direction of force. (+ work by force)
2. an object is free falling downwards (+ work by gravitational force)

negative
acceleration of body opposite of force applied

1. A rope pulls an object in the direction of force (- work by friction)
2. Water is being drawn out of well (- work by gravity)

zero work
force applied at 90 degree to acceleration of body

1. A body on a horizontal table is being pulled forwards ( work by gravity is zero)
2. A man with a load on his head walks on horizontal ground (work by gravity is zero)